Motor fuel compositions



United States Patent" 7 2,897,070 MOTOR" FUEL COIVIPOSIII' ONS sau a-n Newman and ReBert-Y. Heisl'e'r',- Fishkill, N.Y.,

- a'ssignors-to Texaco Inca, a corporation of Delaware No Drawing. mplication-.May 14, 1957 sen-um. 658,960

I 7 Claims. ((21. 44 63).

This invention relates to an improved thotor fuel composition. More particularly, it relates to a motor fuel containing a minor amount of certain epoxy esters of monoethyl'enicfatty" acids to improve the cleanliness properties of the fuel. I

With the continuous development of improved high compression automotive" engines, thedemand for fuels having greater cleanliness properties also increases. The present invention is one which meets/this need.

The improved motor fuel of this invention contains an epoxide of an aliphatic ester'of amonoethylenic fatty acid containing. from 12 to.22 carbon-atoms inan amount 'sufi'icient toimprove the cleanliness properties of the fuel. The epoxy-esters are derived from monoaliphatic alcohols containing from 1 to carbon atoms, glycols containing from- 2 to-4 carbon atoms, and glyeerine', respectively. The epoxide concentration generally falls between 0.01 to 1.0 vol. percent of the fuel and preferably between 0.07 to 0.3 vol. percent.

Epoxides of esters of the following acids are useful in the fuels of this invention: lauroleic, myristoleic, palmitoleic, 9-heptadecenoic, oleic, elaidic, ricinoleic, ricinstearoleic, petroselenic, vaccenic, and erucic. Of the above epoxides of monoethylenic fatty acid esters, that epoxide formed with ricinoleic acid is preferred based on availability and the performance of this epoxide as a fuel additive.

Examples of the alcohols which are useful in forming epoxy esters of the invention include methyl, ethyl, propyl, isoprophyl, butyl, isobutyl, n-amyl, isoamyl, ethylhexyl, and decyl. Ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, trimethylene glycol, and glycerine are also used to form the epoxy esters of the invention. The preferred compounds which are useful as fuel additives in accordance with this invention are alkylepoxyhydroxy stearates and alkylepoxyacetoxy stearates, wherein the alkyl portion has from 1 to 4 carbon atoms, and epoxyacetoxy stearin. These compounds are esters of ricinoleic acid. An important source from which ricinoleic acid is obtained is castor oil which consists primarily of the triglyceride of ricinoleic acid. This triglyceride is also used in the formation of the abovementioned stearin compound.

The epoxides used in the fuels of this invention are generally prepared by controlled oxidation of esters of monoethylenic fatty acids during which the ethylenic bond is converted to form an epoxy group. The more common method used to convert the unsaturated compounds to epoxy compounds consists of the use of per formic acid or peracetic acid as oxidizing agents. Generally, compounds selected from the class consisting of solutions of hydrogen peroxide in fatty acids of from 1 to 4 carbon atoms, fatty peracids of from 1 to 4 carbon atoms, and perbenzoic acid are useful as oxidizing agents. The epoxy compound is formed by contacting the monoethylenic compound with the oxidizing agent and allowing the resulting mixture to stand until the epoxide group has formed. Other methods of carrying out epoxidation lar weight fatty acid having from 2 to 5- carbon atoms,

ite. a'cetic propionicfbutyric, and" pentanoic; however, fatty acids havin up to-10 carbon atoms are used.

The motor fuels which are improved by the compounds of invention are gas'olines' including straight run, aromatic, thermally cracked, 'catalytically cracked, hydroformed, reformed; or blends of any or all of these types of hydrocarbons. These asoiines norm-ally contain up to 3 ml. of tetrae'thyl lead as air antiknock' additive. Other types of gasoline inhibitorswhich are also normally present in the fuel 'm'ay be usedin the fuel composition of this invention. The following table shows the results in the modified Chevrolet deposits CRC-FL-'21-650test; In this test the engine parts are rated "on a numerical basis of one through ten, the-number 10' being the cleanest possible rating for a part and the numbers 9 down throu h 11 "cracked Stock, illi'i'd tia'talyficall y cracked stock, and

straight run gasoline. This base fuel had an 87.0 ASTM research octane rating, contained 2.90 ml. of TEL per gallon, had an API gravity of 58.0, and a boiling range between 106 F. and 396 F. The base fuel was negative in the ASTM test of 530 minutes minimum. It also contained minor amounts of gasoline inhibitors, namely, N,N'-di-secondary butyl-p-phenylenediamine, lecithin, and N,N-di-salicylidene-l,Z-diaminoproprane. In all the runs in Table I, the laboratory engines in the modified Chevrolet deposits-CRC-FL-2-650 test were lubricated with advanced custom made Havoline 20-20W, a heavy duty type oil meeting Supplement I requirements and manufactured by The Texas Company.

It can be seen from the above table that the epoxy type compounds of this invention lend excellent cleanliness properties to the base fuel.

It is realized that related type compounds have been used as motor fuel additives for one purpose or another and in order to show that the epoxy group or groups in the additives of this invention are responsible for the excellent properties of the additive compound the following table is set forth, showing the results of the modified Chevrolet deposits testCRC-FL-2-650 on fuel compositions of the prior art. The base fuel and engine oil which is used in this test is the same as used in the tests reported in the foregoing Table I.

A review of the results in the above Table 11' clearly demonstrates that the epoxy group is necessary for the improved cleanliness properties lent to the base fuel.

The epoxy compounds of this invention will alsoreduce low temperature deposits in diesel fuels and improve the thermal stability of jet fuels when incorporated .therein in minor amounts.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and

therefore, only such limitations should be imposed as are indicated in the appended claims. I

We claim:

1. A normally liquid hydrocarbon fuel containing an epoxide of an aliphatic ester of a'monoethylenic fatty acid having from 12 to 24 carbon atoms wherein the aliphatic portion is the residue of a compound selected from the group consisting of aliphatic hydrocarbyl alcohols having from 1 to 10 carbon atoms, glycols, and

glycerine, said epoxide being present in an amount sufficient to suppress the deposit forming tendencies of the fuel.

' 2. A normally liquid hydrocarbon fuel containing an epoxide of an aliphatic ester of ricinoleic acid wherein the aliphatic portion is the residue of a compound selected from the group consisting of aliphatic hydrocarbyl alcohols having from 1 to 10 carbon atoms, glycols, and glycerine, said epoxide being present in an amount sufficient to suppress deposit forming tendencies of the fuel.

3. A normally liquid hydrocarbon fuel as described in claim 2 wherein the aliphatic portion is the residue of aliphatic hydrocarbyl alcohols having from 1, to 4 carbon atoms.

4. A normally liquid hydrocarbon fuel as described in claim 2 wherein the aliphatic portion is the residue of glycerine.

5. A normally liquid hydrocarbon fuel in the gasoline range containing from 0.01 to 1 percent by volume of an epoxide of alkyl ester of ricinoleic acid wherein the alkyl group has from 1 to 4 carbon atoms and the hydroxy radical on said acid has been esterified with a fatty acid having from 2 to 5 carbon atoms.

6. A normally liquid hydrocarbon fuel in the gasoline range containing from 0.01 to 1 percent by volume of a tri-epoxide of a tri-glyceride of ricinoleic acid.

7. A normally liquid hydrocarbon fuel as described in claim 6 wherein the hydroxy groups on the ricinoleic acid portion of the molecule have been esterified with fatty acids containing from 2 to 5 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 2,548,347 Caron et al Apr. 10, 1951 2,559,177 Terry et al July 3, 1951 FOREIGN PATENTS 749,505 Great Britain May 30, 1956 

1. A NORMALLY LIQUID HYDROCARBON FFUEL CONTAINING AN EPOXIDE OF AN ALIPHATIC ESTER OF A MONOETHYLENIC FATTY ACID HAVING FROM 12 TO 24 CARBON ATIMS WHEREIN THE ALIPHATIC PORTION IS THE RESIDUE OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC HYDROCARBY ALCOHOLS HAVING FROM 1 TO 10 CARBON ATOMS, GLYCOLS, AND GLYCERINE, SAID EPOXIDE BEING PRESENT IN AN AMOUNT SUFFICIENT TO SUPPRESS THE DEPOSIT FORMING TENDENCIES OF THE FUEL. 